Sending animations by email

Can you help?, just sent an email to friends in Canada, & for fun tried to send a cartoon animation, from "My Pictures" but when I opened the attachment in my Sent Messages [Outlook Express] the image was static, no movement.
On an earlier occasion, I sent a short video clip of the Mars Lander [2 or 3 seconds] & it arrived AS an animation
Could seeing it in my Sent Messages, would have appeared static, this end, but arrived OK on receipt?
What I am really saying, I suppose is, am I doing it correctly? I have "Smiley Central", they're OK.
Thanx.

What sort of a file is it? Outlook doesn't have to support every conceivable animation format. But if the animation plays on your comp and you sent the file intact then it will play on the other side as well.

Well, Nodsu, I did try sending the same animation to myself, as you suggested [thanx], with the same result, no movement,.....as to what sort of file, I'm not sure, I just put "animations" on Google, & logged on to one of the sites, can't remember which, the animation worked there, & I sent it to My Pictures, then opened, & "sent to mail recipient" on Outlook Express.